Agent Scott Boras has the prize of free agency in Max Scherzer, and Boras has taken to touting his client’s “pitching odometer.” Boras explained to Jon Heyman of CBS Sports, “[Scherzer] really has the [arm] of a 25 or 26 year old. This is like signing a 25 or 26-year-old pitcher.”

Perhaps reflecting what is found in Scherzer’s binder, Heyman cited the following stats:

“Did you know Scherzer, 30, has thrown 20,954 pitches, to 26,321 for Jon Lester and 29,461 for James Shields, the other top two free-agent pitchers in a top-heavy market containing three aces?”

Scherzer has thrown 8,507 fewer pitches than Shields and 5,367 fewer than Jon Lester. This difference may seem relevant, but in the end it will not matter. Instead, the focus should be on the trio’s birth date.

Context For Number Of Pitches Thrown

When looking at the total number of pitches, the zeros get in the way. For each game started, an ace will throw about 100 pitches. Most aces will start 30+ times a season, so each healthy ace-level pitcher can expect to throw at least 3,000 pitches in a season. The number could grow even higher with longer starts, more regular season starts and postseason games. Just using 3,000 pitches for a season and looking at each pitcher’s age, Boras’ difference can be explained by prorating the pitches thrown back to their age-29 season (Scherzer’s age at the end of last season).

The number of pitches thrown really just comes down to age. Scherzer’s arm had less mileage on it than Lester’s arm at the same age, but more than Shields. The difference of 8,500 pitches may seem like a ton, but for pitchers four years apart in age, the number is completely reasonable.

Pitches Thrown And Likelihood Of Next-Season DL Stint

Now, is there a magic number of pitches when a pitcher’s arm just quits being healthy? Is 25,000 pitches the point? 30,000? My study finds that no magic number exists. Actually, the opposite is true.

I looked at the career pitches thrown by pitchers from 2001 to 2012, then put the pitchers into 3,000-pitch groups and to find their chances of a DL stint next season. Here are the DL percentages for pitchers as they put more mileage on their arms. (Note: 39% of all established pitchers will go on the DL at some point the next season. (n) refers to the number of pitcher-seasons in the sample.)

It may not seem intuitive that pitchers will have a smaller DL chance as they throw more, but they do. At 24,000 pitches, a pitcher has been productive and healthy enough to be in the league around eight seasons. Besides just the number of DL stints, the time spent on the disabled list is just as important. The pitchers could go on the DL and stay there because of a major injury. If high-pitch pitchers were staying on the DL longer, the average number of days would be seen going up. Instead, they decline.

Pitches Thrown And Expected Future Innings Pitched

The three pitchers in question — Scherzer, Lester, and Shields — are each looking for a multi-year deal. How many innings can teams expect out of these pitchers in the future? Looking at the pitches a pitcher has thrown in his MLB career from 2001 to 2009, here are the innings thrown in the next five seasons.

Just because a pitcher has a ton of mileage on his arm doesn’t mean he is about to break down. He could continue to throw for years to come. The more pitches a pitcher has thrown, the better the chances he continues to throw. The three pitchers in question have passed the threshold of being healthy and good.

2015 DL Chances For Scherzer, Lester, Shields

Every pitcher (including these three) will eventually break down, we just don’t know when. An injury risk can be assigned to every pitcher. I have used a DL chance formula to determine the chance a pitcher will end up on the DL withaccurateresults. Using the formula, here their DL chances for 2015.

These three pitchers each have health (no recent DL stints) and a history of being able to make about 33 starts per season on their side. The only difference among them is age, which makes Scherzer the least likely to end up on the DL.

Boras continues to mention Scherzer’s pitching odometer as an advantage over Lester and Shields. However, the number of pitches thrown is not indicative of future injury. A high number shows the pitcher can hold up to the grind of being able to successfully throw for full seasons. The main issue between the three pitchers is age. Scherzer is four years younger than Shields. Scherzer’s body may still be able to hold up a bit better than the other pair, but they are still some of the healthiest pitchers in the league. The debate about the trio’s durability should begin and end with age.

Some ideas are better in theory than in practice. I was tasked a while back by MLBTR owner Tim Dierkes to come up with a free agent salary system similar to the one Matt Swartz created for arbitration salaries. To put it simply, it was a failure. After coming to a agreement, Tim and I decided to scrap the idea and go our separate ways…until about a week ago when I decided to look at the problem a different way.

By using a weighting of similar production and age, a player's contract can be estimated by using a few comparable contracts. It is way too close to the hot stove season to create an estimate for all players, but I was able to scrap together a list starting pitcher salary estimates.

Note: The salaries are based on inflation-adjusted 2013 salaries. If salaries increase 10% across the board this offseason, the values need to be adjusted accordingly. A confidence value is added. The closer the value is to 0, the more pitchers are similar in production to the pitcher in question.

Overall, the values hold up decently. The Similarity Projections estimate almost the same length in contracts, but thinks about $20M more will be spent. Also, with the the years in decimal format, it can be seen how uncertain a player may be in getting a certain number of years on his deal. For example, I have Tim Hudson at 1.6 years and $17.3M. Adjusting those values to one year, he gets $10.8M. It would increase to $21.6M for two years.

Individually, nothing seems completely out of whack. The one contract with the largest disagreement so far is Scott Kazmir's. Basically, there aren't many pitchers that don't pitch at all for two straight seasons and then come back to post an ERA near 4.00. The three most similar pitchers were Chris Capuano (2011), Jake Westbrook (2011) and Carl Pavano (2010). The trio averaged 155 innings in their comeback season and only 26 innings in the two seasons before their comeback. While I used more than three samples for the above value, the three averaged a salary of $9.4MM for 1.3 years (or adjusted to $7.3M for one season or $14.5M for two seasons).

Also, Roy Halladay's projected salary seems a bit out of place, but not many pitchers his age have gotten huge guarantees after the season he had last year. One of the top comparable contracts was the one Roy Oswalt signed in in 2012 at $5MM. Oswalt was younger and was coming off a better season.

The elephant in the room is Matt Garza. Demand has been limited in the past for starters who have averaged only 150 innings over the past three seasons. Unreliable pitchers have unreliable contracts. In terms of innings total, he is getting lumped in with the like of Shaun Marcum and Francisco Liriano. For example, last season Liriano had thrown 480 innings combined in the three previous seasons, with a noticeably worse ERA, but ended up with only a guaranteed 1-year deal for only 1MM. However, prior to his most recent contract, Jorge De La Rosa had similar numbers and received a three-year, $32MM deal. Right now, I think expectations may be a bit high on Garza's salary, since teams are willing to pay more for a reliable starter.

The model was just a year off with Lincecum, predicting $47.4MM over 2.9 years. That is equivalent to a a two-year, $32.7MM contract. The Lincecum deal is the first salary to determine how much salary inflation there is this season. His two-year, $35MM deal works out to 7% inflation. It is way too early to set an exact inflation amount, but it is something to keep an eye on.

The best part about this finding is that we should be able to complete the projection model well in advance of free agency next season, which could lead to a greater number of predictions. At the very least, the starting pitcher salaries that are handed out this offseason should serve as a reference point for future studies that will allow us to better set expectations for the free agent market.